Living systems are incredibly diverse in size, shape, environment, and behavior. It is estimated that there are between 10 million and 100 million different species. Despite this wide variety of organisms, it remains difficult to define what it means to say something is alive. Which of the following can be described as the smallest living unit? a. DNA b. cell c. organelle d. protein ANS: b DIF: Easy REF: 1.1 OBJ: 1.1.b Outline, with examples, ways in which cells share a basic fundamental chemis-try. MSC: Understanding 2. The central dogma provides a framework for thinking about how genetic information is copied and used to produce structural and catalytic components of the cell. From the choices below, select the order of biochemical processes that best correlates with the tenets of the central dogma. a. replication, transcription, translation b. replication, translation, transcription c. translation, transcription, replication d. translation, replication, transcription ANS: A DIF: Easy REF: 1.1 OBJ: 1.1.c Explain how the relationship between DNA, RNA, and protein—as laid out in the central dogma—makes the self-replication of living cells possible. MSC: Understanding 3. Proteins are important architectural and catalytic components within the cell, helping to determine its chemistry, its shape, and its ability to respond to changes in the environment. Remarkably, all of the different proteins in a cell are made from the same 20 __________. By linking them in different sequences, the cell can make protein molecules with different conformations and surface chemistries, and therefore different functions. a. nucleotides b. sugars c. amino acids d. fatty acids ANS: C DIF: Easy REF: 1.1 OBJ: 1.1.b Outline, with examples, ways in which cells share a basic fundamental chem-istry. MSC: Remembering 4. Which statement is NOT true about mutations? a. A mutation is a change in the DNA that can generate offspring less fit for survival than their parents. b. A mutation can be a result of imperfect DNA duplication. c. A mutation is a result of sexual reproduction. d. A mutation is a change in the DNA that can generate offspring that are as fit for survival as their parents are. ANS: C DIF: Easy REF: 1.1 OBJ: 1.1.d Summarize how the processes of mutation and selection promote the gradual evolution of individuals best suited for survival in a wide range of habitats. MSC: Analyzing